Alleviator



Dec. 21, 1954 w 1', KNAUTH I 2,697,451

ALLEVIATOR Filed Oct. 2, 1955 IN VEN TOR.

A 7'TOR/VE Y United SW68 Patent Q ALLEVIATOR Walter T. Knauth, Houston, Tex.

Application October 2, 1953, Serial No. 383,766

2 Claims. (CL 138 -30) This invention relates to an alleviator, or shock absorber, particularly adapted for use in connection with fluid conducting pipe lines through which the fluid is forced, in pulsations, by means of reciprocating pumps or other, similar sources of pressure.

This application is a continuation-in-part of a previous application Serial No. 125,243, filed November 3, 1949; by the same applicant.

An object of the invention is to provide an alleviator adapted to be interposed between the pump and the conducting line, or incorporated into the line itself and which is effective to absorb excessive pressures and restore abnormally low pressure and to thus protect the line from the shocks due to variations in pressures.

Another object of the invention is to provide analleviator of such construction that air or gas may be utilized as a dampening agent to absorb the shocks and which is also of. such construction as to be adapted for use on lines carrying fluids containing abrasive materials or foreign matter.

Another object of the invention is to provide an alleviator having an intermediate chamber containing clean operating fluid which acts as a damper.

A further object of the invention is the provision of an alleviator having a casing provided with a gas chamber, an intermediate for liquid which is in communication with the gas chamber and from which a body of liquid extends at all times into the gas chamber, sa d liquid chamber also having an inlet space connected in communication with a liquid conducting. line, and a flexible diaphragm in the liquid chamber separating the inlet space from said body of liquid, whereby the diaphragm is at all times covered on bothsides with liqu d.

Another object of the invention is to provide an alleviator constructed in the manner described above wherein means is provided for closing the inlet' of the liquid chamber against outflow of liquid from said inlet space to limit the movement of the diaphragm in one direction in the liquid chamber.

A further object of the invention is the provision of an alleviator constructed in the manner described above and wherein means isprovided for causing the liquid to flow uniformly into and out of the liquid chamber from and to the gas chamber to cause the diaphragmto be subjected to uniform pressure throughout its area during the operation of the apparatus. I

Another object of the invention s to provide; an alleviator having the construction described above, wherein means is provided for causing the liquid to: flow uniformly into and out of the inlet sp'acefrom a-ndto the liquid conducting line and also wherein means is provided for limiting the movement of the diaphragm upon the outflow of liquid from the inlet space to the liquid conducting line.

A still further object is to provide an alleviator wherein the intermediate liquid dissipates heat from the diaphragm resulting from rapid flexing.

The diaphragm being located between two bodies of liquid, the migration of gas through the diaphragm will be prevented.

Other objects and advantages will be apparent from the following specification, which is llustrated by the accompanying drawings, wherein the invention is illustrated by a single side elevational Vl6W partly broken away and partly in cross-section showing a preferred construction and arrangement of the parts.

Referring now more particularly to the drawings, the

2,697,451 Patented Dec. 21, 1954 2 numeral 1 designates the casing as a whole, which, in the present illustration, is iorrned with upper and lower chambers 2, 3.

The lower end of the casing is composed of separate casting, which is titted to me ad acent part or the casing above and which is secured thereto oy an annular clamp 4 which is screwed onto one or said sections and which has an inside shoulder 5 engageaoie against the corresponding external shoulder 0 carried uy the other secnon or the casing 1. there is a ClICUlctI' diaphragm 7, which is prere'raoiy formed or ruooer or similar material and which spans the lower chamber 3. it has a marginal rib as which isclarnped between said separate sec ons or the casing, the abutting parts or said sections having grooves LO receive said no so as to anchor the rib against detachment and also to rorm a lean-proof joint between said parts. Any other suitable ty e of diaphragm maybe employed such as an ordinary yieldable partition or a diaphragm 1n the general form or a bellows could be used.

'lhe casing is prererably formed with a restricted portion, indicated at 9,- approximately midway between its end, which portion has an annular recess 10, rormed therein into which a perrorated plate 12 is fitted and secured therein in any suitable manner, as by screws 14.

Within the lower chamber 3 there is a perforated plate 16, securedtherein in any suitable manner, as by means of screws 16, and the diaphragm has attached thereto a centrally located shoe 20, by means of a faStD ing element 22, which may take the form of a rivet, bolt, or other suitable means, and which passes through backing plates 24 and 26, one of which is located on the upper side of the diaphragm, and the other of which is located at the lower side of the shoe. 'lhe shoe 20, is preferably formed of a suitable resilient material, such as rubber, or the like, and may have layers otreiriforcing fabric therein to secure the requisite rigidity and wearing quality. The shoe is of a size and shape to engage the perforated plate 16, when the diaphragm is in its lowermost position, to effectively seal the plate against outflow of liquid therethrough.

lh'e space within the casing beneath the diaphragm 7 serves as an inlet space into and out of which liquid from a liquid conducting line may flow through the pipe 28, which is connected in communication with the lower end of the casing.

The chamber 3 may be filled with a suitable liquid, and such liquid preferably extends to a level above the perforated plate 12, within the chamber 2, which may be filled with air or gas under the required pressure above the liquid.- A sutlicient volume of liquid is preferably employed so if at the level of the liquid will be above the perforated plate 12 when the diaphragm is in its lowermost position,- as illustrated in the drawings, so that the liquidchamber above the inlet space is at all times entirely filled with liquid. The gas may be introduc'ed into the gaschamber 2 through a suitable conn'ectioii, such as that illustrated at 30, which may be opened and closed by means of a valve .32, which is fitted into the connection 30. I

applying the invention to a hydraulic system in which pulsations occur, liquid, such as Water, is introduced into the casing, to fill the liquid chamber above the diaphragm 7, and extending to a level above the perforated plate 12, as indicated in the drawings, so that the level of the liquid will be above the perforated plate when the diaphragm is in its lowermost position with the shoe 20 seated on the lower perforated plate 16 as shown, and the inlet pipe 28 is connected with the system, so that liquid from the system may enter the inlet space of the casing beneath the diaphragm upon the occurrence of a pulsation in the system. In this condition of the apparatus the inlet in the casing beneath the diaphragm 7 will be filled with liquid, so that the diaphragm has a body of liquid in contact with both sides thereof, whereby migration of gas through the diaphragm is efiectively prevented, and heat generated by the flexing and expansion and contraction of the diaphragm during rapid reciprocation of the same will be effectively dissipated and prevented from softening, charring or otherwise adversely aifecting the material of the diaphragm.

It will be apparent that upon the occurrence of a pulsation resulting in an increase in pressure in the 'hydraulic system, liquid therefrom will flow through the inlet pipe 28 into the inlet space of the casing beneath the diaphragm to move the diaphragm upwardly against the weight of the liquid thereabove, and the pressure of the gas chamber, thus effectively cushioning and absorbing the pulsation. Upon a reduction of pressure in the hydraulic system liquid in the inlet space of the casing will flow outwardly through the perforated plate and the inlet pipe 28 back to the system, and the diaphragm will move downwardly under the combined effect of the weight of the liquid above the diaphragm and the pressure of the gas in the gas chamber to cause the shoe 20, to seat on the perforated plate 16, to close off the inlet space against further outflow of liquid therefrom. It will also be apparent that upon the seating of the shoe 200m the perforated plate 16 further expansion of the diaphragm downwardly is prevented and the diaphragm is also prevented from coming in contact with the plate whereby distortion of the diaphragm, or extrusion of the material thereof through the perforations of the plate will be prevented.

By reason of the provision of the upper and lower perforated plates 12 and 16, it will also be apparent that the movement of liquid in the apparatus will be substantially uniformly distributed throughout the cross sectional area of the same, so that pressure will be uniformly applied to the surfaces of the diaphragm, whereby uneven stretching or distortion of the same will be prevented. Other suitable means, such as screens or foraminous elements of some other type may of course be employed instead of the perforated plates 12 and 16 illustrated, and the positions which they occupy may be somewhat varied, as may be desirable orexpedient, from the positions shown. In the present illustration the plate 12 substantially divides the gas chamber from the liquid chamber.

In the event that it should become necessary to disassemble the apparatus for purposes of replacement and repair the annular clamp 4, may be unscrewed and the parts of the casing separated, whereupon the diaphragm 7 may be readily removed and replaced, and the perforated plates 12 and 16 can be easily removed and reinserted should this be necessary.

It will thus be apparent that the invention constructed as described above, provides an alleviator which is of simple design and rugged construction, having few parts, and in which the flexible diaphragm is protected against distortion, stretching or overheating.

While the invention has been disclosed herein in connection with a certain specific embodiment of the same, it will be understood that this is intended by way of illustration only, and that numerous changes can be made in the construction and arrangement of the various parts, without departing from the spirit of the invention or the scope of the appended claim.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. An alleviator for absorbing pulsations and alleviating vibration'in a pulsating, pressurized liquid line and comprising a casing including two vertically disposed, rigid walled chambers with the lowermost chamber adapted to be connected to said line to provide an inlet extending from the path of liquid flow in the line, perforate means across the intercommunication between chambers and a similar perforate means across said inlet,

, tially spherical inner surfaces whereby, as line liquid fiows into said inlet to urge the liquid above the diaphragrn upwardly, said upper chamber has an increasing gas-l1qu1d contact area to dampen surging of said upper chamber liquid and of said diaphragm, and whereby, as

said liquid recedes and liquid flows substantially uniformly through said upper and lower perforate means,

billowing of said diaphragm is reduced as the horizontal cross-sectional area of said upper liquid around said diaphragm first gradually increases as said diaphragm recedes to pass the central horizontal plane of said lower chamber and then decreases as said diaphragm further descends as said line liquid flows downwardly through said inlet, and valve means connected to said diaphragm to seat upon said perforate means across said inlet and thereby close off said inlet from said line liquid while at least partially preventing said diaphragm from being drawn and urged into said inlet perforate means and into said inlet.

2. An alleviator for absorbing pulsations and alleviating vibration in a pulsating, pressurized liquid line and comprising a casing including two vertically disposed chambers with the lowermost chamber adapted to be connected to said line to provide an inlet extending from the path of liquid flow in the line, perforate means across the intercommunication between chambers and a similar perforate means across said inlet, a flexible diaphragm dividing the lower chamber and forming with the casing 21 space on the inlet side of said diaphragm and communicating with said inlet, a body of liquid in said lower chamber in contact with the other side of said diaphragm and extending into said upper chamber, compressed gas in said upper chamber above said liquid, said lower chamber providing a smooth, substantially spherical inner surface whereby after line liquid in a pulsation is forced through said inlet to force said diaphragm and the liquid thereabove upwardly and said liquid then recedes as the pulsation peak passes and said line liquid flows downwardly through said inlet, billowing and surge of said diaphragm is reduced as the horizontal cross-sectional area of said upper liquid around said diaphragm first gradually increases as said diaphragm recedes to pass the central horizontal plane of said lower chamber and then decreases as said diaphragm further descends as said line liquid flows downwardly through said inlet, and valve means connected to said diaphragm to seat upon said perforate means across said inlet and thereby close off said inlet from said line liquid while at least partially preventing said diaphragm from being drawn and urged into said inlet perforate means and into said inlet.

References Cited in the file of this patent UNITED STATES PATENTS 

